An important component outside of PowerFlex that enables a flexible consumption model for Kubernetes is the PowerFlex CSI driver, developed as a part of the Dell Kubernetes strategy. After loading the CSI driver for PowerFlex into Kubernetes, it can be used to provision persistent volumes from the underlying PowerFlex storage resource. If the Kubernetes deployment is running low on PowerFlex storage resources, you can seamlessly add PowerFlex storage nodes to increase the system capacity and performance.

The CSI driver connects the PowerFlex system and Kubernetes deployments. It is a storage broker which dynamically provisions volumes from PowerFlex through the PowerFlex API gateway to the Kubernetes cluster. Once the volume is available on PowerFlex, it is immediately mapped to the requesting pod. If a pod is destroyed or rescheduled, the CSI plug-in ensures that the volumes are remapped upon that pod’s rescheduling. 

Customers running Kubernetes clusters on PowerFlex make use of the Dell Container Storage Modules (CSM), which extend the CSI driver capabilities. These modules:

• Provide enterprise storage capabilities to Kubernetes for cloud-native stateful applications. 
• Reduce management complexity, so that developers can independently use enterprise storage with ease and automate daily operations. 
• Extends storage functionality and capabilities beyond using the CSI driver alone. 

At present, these modules include replication, observability, authorization, application mobility and resiliency. 

PowerFlex supports multiple operating systems, different deployment options on-premises and public cloud deployment model (currently available in AWS). PowerFlex is validated with industry’s leading Kubernetes distributions as shown in the Figure 3. 

Figure 3: PowerFlex for different Kubernetes distributions